U.S. patent number 6,848,478 [Application Number 10/326,882] was granted by the patent office on 2005-02-01 for flexible tube.
This patent grant is currently assigned to Calsonic Kansei Corporation. Invention is credited to Tadashi Nagai.
United States Patent |
6,848,478 |
Nagai |
February 1, 2005 |
Flexible tube
Abstract
A small-diameter part in the vicinity of a center of a bellows
portion in an axial direction has a smaller diameter. A tip end of
the small-diameter part contacts at a point A with an outer
peripheral face of an interlock pipe. The interlock pipe vibrates
with using the point A and points B in both ends as fulcrums. The
addition of the point A reduces distance between the fulcrums. In
accordance with this reduction, deflection amount of the interlock
pipe is reduced and vibration amplitude of the interlock pipe is
decreased. Therefore, the interlock pipe does not contact with the
bellows portion so that troubles such as noises can be prevented
from occurring.
Inventors: |
Nagai; Tadashi (Tokyo,
JP) |
Assignee: |
Calsonic Kansei Corporation
(Tokyo, JP)
|
Family
ID: |
19188564 |
Appl.
No.: |
10/326,882 |
Filed: |
December 23, 2002 |
Foreign Application Priority Data
|
|
|
|
|
Dec 25, 2001 [JP] |
|
|
P.2001-391845 |
|
Current U.S.
Class: |
138/112; 138/114;
138/121; 138/122; 138/135; 138/148 |
Current CPC
Class: |
F01N
13/1816 (20130101); F16L 27/11 (20130101); F16L
27/1004 (20130101) |
Current International
Class: |
F16L
27/10 (20060101); F16L 27/11 (20060101); F16L
27/00 (20060101); F16L 009/18 () |
Field of
Search: |
;138/112,114,121,122,135,148 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
|
|
|
|
|
|
|
0 875 669 |
|
Nov 1998 |
|
EP |
|
2 032 068 |
|
Nov 1970 |
|
FR |
|
Primary Examiner: Hook; James
Attorney, Agent or Firm: Foley & Lardner LLP
Claims
What is claimed is:
1. A flexible tube comprising: a bellows tube comprising: a bellows
portion formed of a plurality of first small-diameter parts of a
first inner diameter; and straight portions formed at a first and a
second end of the bellows tube, respectively; an interlock pipe in
which a plurality of annular plate members or spirally wound band
plates are flexibly coupled at side edges thereof to one another
through an interlock mechanism, wherein the interlock pipe is
disposed inside the bellows tube, and wherein the bellows tube and
the interlock pipe have a common axis; and a restriction member
disposed on the bellows portion, for serving as a fulcrum to
restrict a vibration amplitude of the interlock pipe when the
interlock pipe is vibrated, wherein an inner diameter of the
straight portions of the bellows tube is smaller than the first
inner diameter of the first small-diameter parts of the bellows
portion, wherein inner peripheral surfaces of the straight portions
are fixed to an outer surface of the interlock pipe, wherein the
bellows portion comprises a second small-diameter part having a
second inner diameter which is smaller than that of the first inner
diameter of the first small-diameter parts; and wherein the
restriction member is a buffer member disposed between an inner
peripheral tip of the second small-diameter part and the outer
peripheral surface of the interlock pipe.
2. The flexible tube according to claim 1, wherein the restriction
member is a plurality of restriction members arranged in the axial
direction at a predetermined interval.
3. The flexible tube according to claim 1, wherein the second
small-diameter part has an axial width that is substantially the
same as the first small-diameter parts.
4. A flexible tube comprising: a bellows tube comprising: a bellows
portion formed of a plurality of first small-diameter parts of a
first inner diameter; and straight portions formed at a first and a
second end of the bellows tube, respectively; an interlock pipe in
which a plurality of annular plate members or spirally wound band
plates are flexibly coupled at side edges thereof to one another
through an interlock mechanism, wherein the interlock pipe is
disposed inside the bellows tube, and wherein the bellows tube and
the interlock pipe have a common axis; a restriction member
disposed on the bellows portion, for serving as a fulcrum to
restrict a vibration amplitude of the interlock pipe when the
interlock pipe is vibrated, wherein an inner diameter of the
straight portions of the bellows tube is smaller than the first
inner diameter of the first small-diameter parts of the bellows
portion, wherein inner peripheral surfaces of the straight portions
are fixed to an outer surface of the interlock pipe, wherein the
bellows portion has a plurality of second small-diameter parts
having a second inner diameter, the second inner diameter being
smaller than the first inner diameter of the first
small-diameter-parts; and wherein the restriction member is a
buffer member disposed between an inner peripheral tip of at least
one of the small-diameter parts having the larger inner diameter
and the outer peripheral surface of the interlock pipe, and wherein
the second small-diameter parts flank the buffer member to hold the
buffer member in the axial direction.
5. The flexible tube according to claim 4, wherein the restriction
member is a plurality of restriction members arranged in the axial
direction at a predetermined interval.
6. The flexible tube according to claim 4, wherein the bellows
portion further includes a third small-diameter part having a third
inner diameter, the third inner diameter being substantially the
same as the first inner diameter of the first small-diameter parts,
wherein the buffer member is disposed between the tip of at least
the third small-diameter part and the outer peripheral surface of
the interlock pipe, and wherein the second small-diameter parts are
disposed on axial opposing sides of the third small-diameter part
and the buffer member.
7. The flexible tube according to claim 6, wherein the buffer
member contacts the outer peripheral surface of the interlock pipe
without being fixed to the interlock pipe.
8. A flexible tube comprising: a bellows tube comprising: a bellows
portion formed of a plurality of first small-diameter parts of a
first inner diameter; and straight portions formed at a first and a
second end of the bellows tube, respectively; an interlock pipe in
which a plurality of annular plate members or spirally wound band
plates are flexibly coupled at side edges thereof to one another
through an interlock mechanism, wherein the interlock pipe is
disposed inside the bellows tube, and wherein the bellows tube and
the interlock pipe have a common axis; and restriction means
disposed on the bellows portion, for serving as a fulcrum to
restrict a vibration amplitude of the interlock pipe when the
interlock pipe is vibrated, wherein an inner diameter of the
straight portions of the bellows tube is smaller than the first
inner diameter of the first small-diameter parts of the bellows
portion, wherein inner peripheral surfaces of the straight portions
are fixed to an outer surface of the interlock pipe, wherein the
bellows portion comprises a second small-diameter part having a
second inner diameter which is smaller than that of the first inner
diameter of the first small-diameter parts; and wherein the
restriction member is a buffer member disposed between an inner
peripheral tip of the second small-diameter part and the outer
peripheral surface of the interlock pipe.
9. A flexible tube comprising: a bellows tube comprising: a bellows
portion formed of a plurality of first small-diameter parts of a
first inner diameter; and straight portions formed at a first and a
second end of the bellows tube, respectively; an interlock pipe in
which a plurality of annular plate members or spirally wound band
plates are flexibly coupled at side edges thereof to one another
through an interlock mechanism, wherein the interlock pipe is
disposed inside the bellows tube, and wherein the bellows tube and
the interlock pipe have a common axis; and a restriction means
disposed on the bellows portion, for serving as a fulcrum to
restrict a vibration amplitude of the interlock pipe when the
interlock pipe is vibrated, wherein an inner diameter of the
straight portions of the bellows tube is smaller than the first
inner diameter of the first small-diameter parts of the bellows
portion, wherein inner peripheral surfaces of the straight portions
are fixed to an outer surface of the interlock pipe, wherein the
bellows portion has a plurality of second small-diameter parts
having a second inner diameter, the second inner diameter being
smaller than the first inner diameter of the first small-diameter
parts; and wherein the restriction member is a buffer member
disposed between an inner peripheral tip of at least one of the
small-diameter parts having the larger inner diameter and the outer
peripheral surface of the interlock pipe, and wherein the second
small-diameter parts flank the buffer member to hold the buffer
member in the axial direction.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
The present disclosure relates to the subject matter contained in
Japanese Patent Application No.2001-391845 filed on Dec. 25, 2001,
which is incorporated herein by reference in its entirety.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a structure of a flexible tube
including an interlock pipe and a bellows tube.
2. Description of the Related Art
In an exhaust pipe of an engine or the like, a part of the exhaust
pipe is sometimes configured by a flexible tube in order to improve
easiness of layout, etc. FIG. 5 shows an example of such a flexible
tube. A flexible tube 1A has an outer blade 3, which is placed on
the outer peripheral side of a bellows tube 9 having a bellows
portion 9c, and an interlock pipe 4, which is placed on the inner
peripheral side of the bellows tube 9.
Each of straight portions 2a of the bellows tube 9, and
corresponding one of end portions 3a of the outer blade 3 are
placed with being overlaid on the outer peripheral face of the
interlock pipe 4. A protector 5 is placed on the outer peripheral
side of the end portion 3a of the outer blade 3. The protector 5,
the straight portion 2a, and the end portion 3a are welded to the
outer peripheral face of the interlock pipe 4.
The inner peripheral diameter of the bellows portion 9c of the
bellows tube 9 is set to be larger than that of the straight
portion 2a, so that a gap is formed between the bellows portion and
the outer peripheral face of the interlock pipe 4. Even when the
flexible tube 1A swings due to vibrations of the engine or the
like, therefore, the outer peripheral face of the interlock pipe 4
and the bellows portion 9c are prevented from contacting with each
other.
In a flexible tube 1B which is structured as described above and
has a long total length as shown in FIG. 6, when the flexible tube
1B vibrates, the swing amplitude of the interlock pipe 4 is larger
as the length is larger. As a result, the outer peripheral face of
the interlock pipe 4 and the bellows portion 9c contact with each
other, thereby causing troubles such as noises.
SUMMARY OF THE INVENTION
In view of the problem, it is an object of the invention to provide
a flexible tube in which troubles such as noises are not caused
even when a flexible tube has a long total length and vibrations of
an engine or the like are produced.
According to a first aspect of the invention, there is provided a
flexible tube including a bellows tube, an interlock pipe, and a
restriction member. The bellows tube has a bellow portion and
straight portions, which is formed both ends thereof. The interlock
pipe in which a plurality of annular plate members or spirally
wound band plates are flexibly coupled at side edges thereof to one
another through an interlock mechanism, is disposed inside the
bellows tube to have a common axis. The restriction member is
disposed on the bellow portion and serves as a fulcrum to restrict
vibration amplitude of the interlock pipe when the interlock pipe
is vibrated. Inner diameter of the straight portions tube is larger
than that of first small-diameter parts of the bellow portion.
Inner peripheral surfaces of the straight portions are fixed to an
outer surface of the interlock pipe.
According to a second aspect of the invention, the bellow portion
has a second small-diameter part, inner diameter of which is
smaller than that of the first small-diameter parts. An inner
peripheral tip of the second small-diameter part abuts against the
outer peripheral surface of the interlock pipe to define the
restriction member.
According to a third aspect of the invention, the restriction
member is a buffer member disposed between an inner peripheral tip
of at least one of the first small-diameter parts and the outer
peripheral surface of the interlock pipe.
According to a fourth aspect of the invention, the bellow portion
has a second small-diameter part, inner diameter of which is
smaller than that of the first small-diameter parts. The
restriction member is a buffer member disposed between an inner
peripheral tip of the second small-diameter part and the outer
peripheral surface of the interlock pipe.
According to a fifth aspect of the invention, the bellow portion
has third small-diameter parts, inner diameter of which smaller
than that of the first small-diameter part. The restriction member
is a buffer member, which is disposed between an inner peripheral
tip of at least one of the first small-diameter parts and the outer
peripheral surface of the interlock pipe so that the third
small-diameter parts holds the buffer member in the axial
direction.
According to a sixth aspect of the invention, the restriction
member is a plurality of restriction members arranged in the axial
direction at a predetermined interval.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a view showing an embodiment of the invention.
FIG. 2 is a view showing vibrations of an interlock pipe.
FIG. 3 is a view showing a second embodiment of the invention.
FIG. 4 is a view showing a third embodiment of the invention.
FIG. 5 is a view showing a flexible tube according to the prior
art.
FIG. 6 is a view showing vibrations of an interlock pipe according
to the prior art.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Next, embodiments of the invention will be described.
FIG. 1 is a section view of an embodiment.
A flexible tube 1 has an outer blade 3 including a braided tube,
which is placed on the outer peripheral side of a bellows tube 2
having a bellows portion 2c, and an interlock pipe 4, which is
placed inside the bellows tube 2. Each of straight portions 2a of
the bellows tube 2, and corresponding one of end portions 3a of the
outer blade 3 are overlaid on the outer peripheral face of the
interlock pipe 4. A protector 5 is placed on the outer peripheral
side of the end portion 3a of the outer blade 3. The outer end
portion of the protector 5 is squeezed so that the inner peripheral
face thereof matches the outer peripheral face of the end portion
3a. The inner end portion of the protector 5 elongates toward the
inner side in the axial direction while the diameter thereof is
expanded to coincide with the usual outer peripheral diameter of
the outer blade 3. The protector 5, the straight portion 2a of the
bellows tube, and the end portion 3a of the outer blade 3 are
welded to the outer peripheral face of the interlock pipe 4.
The usual diameter of the small-diameter parts of the bellows
portion 2c of the bellows tube 2 is set to be larger than the inner
peripheral diameter of the straight portion 2a, so that a gap is
formed between the interlock pipe 4 and the bellows tube 2. In the
bellows portion 2c, a small-diameter part, in the form of a
restriction member, 6a in the vicinity of a center portion in an
axial direction is set to have a smaller diameter. When the
flexible tube 1 is in its natural state, the inner peripheral end
of the restriction member 6a is in contact with the outer
peripheral face of the interlock pipe 4. The contact point between
the restriction member 6a and the outer peripheral face of the
interlock pipe 4 is indicated by A.
The interlock pipe 4 and the tip end of the restriction member 6a
contact with each other at the point A in a rattle-free condition.
Even when the interlock pipe 4 vibrates, troubles such as noises
are not caused in the point A.
The motion of the interlock pipe 4 in the case where the flexible
tube 1 vibrates will be described with reference to FIG. 2.
Since the tip end of the restriction member 6a contacts at the
point A with the outer peripheral face of the interlock pipe 4, the
interlock pipe 4 vibrates with using the point A and points B as
fulcrums. The points B are boundaries between the straight portions
2a in both the ends of the bellows tube 2 and the bellows portion
2c.
The addition of the point A reduces the distance between the
fulcrums. In accordance with this reduction, the deflection amount
of the interlock pipe 4 is reduced, and the vibration amplitude of
the interlock pipe 4 is decreased. Even when the flexible tube 1
has a long total length, any portion of the interlock pipe 4 other
than the point A does not contact with the bellows portion 2c of
the bellows tube 2 because the distance between the fulcrums is
short.
The embodiment is configured as described above. When the flexible
tube 1 vibrates and the interlock pipe 4 swings, the amplitude
thereof can be reduced since the addition of a swing fulcrum by
means of the restriction member 6a. Therefore, the gap between the
interlock pipe 4 and the bellows tube 2 can be reduced. As a
result, the outer diameter of the flexible tube can be made smaller
than that of a flexible tube according to the related art which
uses a bellows tube having uniform crest height (crest height
refers to difference between small-diameter parts and
large-diameter parts in a bellows portion).
When the outer diameter of the flexible tube is set to be equal to
that of the flexible tube according to the related art, the gap
between the interlock pipe 4 and the bellows tube 2 can be reduced,
and in accordance with the reduced gap the crest height of the
bellows tube can be increased. Therefore, the flexibility of the
bellows tube can be improved, and the value of stress produced in
the bellows tube can be reduced. Accordingly, the strength can be
enhanced.
FIG. 3 shows a second embodiment.
A small diameter part which is part of restriction member, 6b in
the vicinity of a center portion of the bellows portion 2c of the
bellows tube 2 in an axial direction, has a smaller diameter than
the usual small-diameter parts. However, the small-diameter part 6b
does not butt against the interlock pipe 4. A restriction buffer
member 7 is attached in a gap between an inner peripheral end of
the small-diameter part 6b and the interlock pipe 4 so that the
small-diameter part 6b restricts the swing of the interlock pipe 4
through the restriction buffer member 7. The restriction buffer
member 7 is attached to a place in the vicinity of a center of the
interlock pipe 4 corresponding to the small-diameter part 6b, by
spot welding or the like.
In the embodiment, the small-diameter part 6b and the buffer member
7 attached to the interlock pipe 4 may constitute the restricting
member in the invention.
The small-diameter part 6b is set to have a smaller diameter so
that it does not butt against the interlock pipe 4. However, the
invention is not limited to this. Alternatively, the diameter of
the small-diameter part 6b may be the same as the diameter of the
usual small-diameter parts, and the restriction buffer member 7 may
be attached in the gap between the inner peripheral end of the
small-diameter part 6b and the interlock pipe 4.
FIG. 4 shows a third embodiment.
A restriction buffer member 10 is placed between in a gap between a
small-diameter part 8, which is part of the restriction member, in
the vicinity of a center of the bellows portion 2c in an axial
direction and the interlock pipe 4. Flanking restriction members
6c, which are provided on both sides of the small-diameter part 8,
diameters such that the flanking restriction members 6c do not butt
against the interlock pipe 4. The restriction buffer member 10 is
clamped between the flanking restriction members 6c to restrict its
axial movement.
According to the configuration, the restriction buffer member 10
held by the flanking restriction members 6c butts against the
interlock pipe 4, whereby the swing of the interlock pipe 4 can be
restricted.
The buffer member 10, and the small-diameter parts 8 and 6c of the
bellows portion 2c may constitute the restricting member in the
invention.
According to the embodiment, since the restriction buffer member 10
is held at both sides by the flanking restriction members 6c, the
restriction buffer member 10 does not slip off even when the
restriction buffer member 10 is not fixed to the small-diameter
part 8 by welding or the like.
In the embodiments described above, one fulcrum of the swing of the
interlock pipe 4 is disposed in the vicinity of the center of the
bellows tube 2 with using the small-diameter part 6a, 6b, 6c, or 8
or the restriction buffer member 7 or 10. Alternatively, a
plurality of fulcrums may be disposed with using a plurality of
small-diameter parts 6a, 6b, 6c, or 8 or restriction buffer members
7 or 10.
The fulcrum of the swing of the interlock pipe 4 is disposed in the
vicinity of the center. Alternatively, the fulcrum may be disposed
in another predetermined position.
In the second embodiment, the restriction buffer member 7 is
attached to the interlock pipe 4. Alternatively, the buffer member
may be fixed to the-small-diameter part restriction member 6b.
According to a first aspect of the invention, since the fulcrum of
the swing of the interlock pipe depends on the usual small-diameter
parts, the distance between the fulcrums is shortened, and hence
the deflection amount of the interlock pipe is reduced. As a
result, the vibration amplitude of the interlock pipe is reduced,
and it is not necessary to excessively enlarge the gap between the
bellows portion of the bellows tube and the interlock pipe, whereby
the size and the like of the flexible tube can be reduced.
According to a second aspect of the invention, vibrations of the
interlock pipe can be restricted by a simple structure without
using an additional member.
According to a third aspect of the invention, since the gap between
the usual small-diameter parts of the bellows portion of the
bellows tube and the interlock pipe may be filled with using a
restriction buffer member 7, 10, troubles such as noises can be
prevented from occurring.
According to a fourth aspect of the invention, troubles such as
noises can be prevented from occurring while the amplitude of the
interlock pipe is restricted more surely.
According to a fifth aspect of the invention, the restriction
buffer member 7. 10 can be held without using an additional member,
and the amplitude of the interlock pipe can be restricted by the
restriction buffer member 7, 10.
According to a sixth aspect of the invention, the number of
fulcrums of vibrations of the interlock pipe may be increased by
disposing a plurality of restricting means, and hence vibrations of
the interlock pipe can be restricted more surely.
* * * * *